Annual report pursuant to Section 13 and 15(d)

Stock-Based Awards Stock-Based Awards (Weighted Average Assumptions Used in Valuation of ESPP Options)(Details)

v3.3.1.900
Stock-Based Awards Stock-Based Awards (Weighted Average Assumptions Used in Valuation of ESPP Options)(Details) - Employee Stock [Member]
12 Months Ended
Dec. 31, 2015
Rate
Dec. 31, 2014
Rate
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]    
Volatility factor 21.70% 22.00%
Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Risk Free Interest Rate 0.12% 0.08%
Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Expected Term 6 months 6 months
Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Expected Dividend Rate 1.90% 1.70%